CVE-2018-7755

Se descubrió un fallo de seguridad en la función fd_locked_ioct en drivers/block/floppy.c en el kernel de Linux hasta la versión 4.15.7. La unidad de disquete copiará un puntero kernel a la memoria del usuario en respuesta a la llamada IOCTL FDGETPRM. Un atacante puede enviar la llamada IOCTL FDGETPRM y utilizar el puntero de kernel obtenido para descubrir la ubicación de los datos y el código del kernel y omitir medidas de seguridad de kernel como KASLR.

An issue was discovered in the fd_locked_ioctl function in drivers/block/floppy.c in the Linux kernel. The floppy driver will copy a kernel pointer to user memory in response to the FDGETPRM ioctl. An attacker can send the FDGETPRM ioctl and use the obtained kernel pointer to discover the location of kernel code and data and bypass kernel security protections such as KASLR.

It was discovered that the nested KVM implementation in the Linux kernel in some situations did not properly prevent second level guests from reading and writing the hardware CR8 register. A local attacker in a guest could use this to cause a denial of service. Fan Wu, Haoran Qiu, and Shixiong Zhao discovered that the associative array implementation in the Linux kernel sometimes did not properly handle adding a new entry. A local attacker could use this to cause a denial of service. Various other issues were also addressed.